title: Water-soluble magnetic CoO nanocrystals functionalized with surfactants as T2-weighed MRI contrast agents in vitro.
abstract: CoO nanocrystals (CoO NCs) were synthesized by thermal decomposition of the cobalt-oleate complex. For biological applications, water-soluble CoO NCs were obtained via a facile phase-transfer method by employing amphiphilic surfactants, such as anionic (sodium dodecyl sulfate, SDS), neutral (Pluronic F127, PF127) and cationic (cetyltrimethyl ammonium bromide, CTAB). Field-dependent magnetization measurements indicated that the type of surfactants around the CoO NCs plays a crucial role in their magnetic properties. Among them, CoO NCs functionalized with PF127 have the largest saturated magnetization (M(s)) of 10.9 emu g(-1). To clarify the potential application in magnetic resonance imaging (MRI), longitudinal relaxivities (r(1)) and transverse relaxivities (r(2)) of the functionalized CoO NCs were investigated in detail. The r(2)/r(1) of CoO NCs functionalized with PF127 is about 26. Therefore, they should be novel excellent potential T(2) contrast agents. Furthermore, methyl thiazolyl tetrazolium (MTT) assays show that they have low cytotoxicity in living cells. In vitro experiment results indicated that they can be taken up by living cells effectively, showing the obvious decrease of the transverse relaxation time T(2) after internalization.
authors.affiliation: The Key Laboratory of Resource Chemistry of ministry of Education, College of Life and Environmental Science, Shanghai Normal University, 100 Guilin Road, Shanghai, 200234, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhou
authors.forename: Cuixia
authors.initials: C
authors.lastname: Zhang
authors.forename: Xuejian
authors.initials: X
authors.lastname: Li
authors.forename: He
authors.initials: H
authors.lastname: Hu
authors.forename: Huixia
authors.initials: H
authors.lastname: Wu
authors.forename: Shiping
authors.initials: S
authors.lastname: Yang
mesh_terms: D001692:Biological Transport; D045744:Cell Line, Tumor; D003035:Cobalt / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D003287:Contrast Media / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D019301:Oleic Acid / Q000737:chemistry; D010087:Oxides / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D003287:Contrast Media; D010087:Oxides; D013501:Surface-Active Agents; D014867:Water; D019301:Oleic Acid; D003035:Cobalt; C060728:cobalt oxide